1. Technical Field
The present invention relates to a technology for a wireless power transfer (WPT) and its application to a wireless chargeable unmanned aerial vehicle (UAV), and more particularly to a technology for wirelessly charging three-phase AC power and a three-phase wireless chargeable UAV system based on the technology.
2. Description of the Related Art
Among the various devices driven by electric energy, there are many devices that need to supply the electric energy frequently through charging. Electric energy is charged in a wired manner in many devices, but in recent years the number of devices charged in a wireless manner is increasing.
For example, the UAV, also known as a “drone”, rotates the propellers by motor power to fly. The UAV has a means for charging electric energy, which is charged and used as a power source as necessary. Recently, interest in wireless charging technology to utilize the advantage of wireless charging method in the UAV is increasing. Conventional wireless charging systems for the UAV have been designed based on a single-phase wireless charging scheme using a single phase inverter. However, the single-phase WPT has poor power transfer efficiency. There is a need for a WPT method of which power transfer efficiency is good.
In general, the UAV is equipped with various electronic components for controlling its flight. A strong electromagnetic field that occurs during wireless charging can cause damages or errors in its electronic components. When a single-phase wireless charging system is applied to the UAV, there is a disadvantage in that, in addition to the disadvantages mentioned above, additional measures are required to prevent the electronic components from the electromagnetic interference (EMI), which causes increase in its weight. There is also a need for measures to solve this problem.